Intersouth Partners, a seed investor in software developer Flatburger, has increased its stake in the company.

Intersouth, which is based in Durham, co-lead a $5 million Series A round investment along with Amplifier Venture Partners in Flatburger. Flatburger is based in Arlington, Va.

Flatburger also disclosed the hiring of Justin Law as its chief technology officer. He was senior director of mobile search at InfoSpace.

“The new funds will enable us to more quickly develop a revolutionary online marketplace for software,” said Bill Phelan, chief executive officer and co-founder of Flatburger. “It is a real testament to our business strategy and relationship with our venture capital partners that they invested significantly more to help us realize Flatburger’s potential.”